The Constellation-X mission, planned for launch in 2013, will feature an array of hard-x-ray tele... more The Constellation-X mission, planned for launch in 2013, will feature an array of hard-x-ray telescopes (HXT) with a total collecting area of greater than 1500 cm at 40 keV. Two technologies are currently being investigated for the optics of these telescopes including ...
ABSTRACT The Constellation-X (Con-X) mission planned for launch in 2015, will feature an array of... more ABSTRACT The Constellation-X (Con-X) mission planned for launch in 2015, will feature an array of Hard X-ray telescopes (HXT) with a total collecting area greater than 1500 cm2 at 40 keV. Two technologies are being investigated for the optics of these telescopes, including multilayer coated Electroformed-Nickel-Replicated (ENR) shells. The attraction of the ENR process is that the resulting full-shell optics are inherently stable and offer the prospect of better angular resolution which results in lower background and higher instrument sensitivity. We are building a prototype HXT mirror module using an ENR process to fabricate the individual shells. This prototype consists of 5 shells with diameters ranging from 150 mm to 280 mm with a length of 426 mm. The innermost of these will be coated with iridium, while the remainder will be coated with graded d-spaced W/Si multilayers. Parts I and II of this work were presented at the SPIE meetings in 2003 and 2004. This paper presents a progress update and focuses on accomplishments during this past year. In particular, we will present results from full illumination X-ray tests of multilayer coated shells, taken at the MPE-Panter X-ray facility.
We present details of an MSFC development program of electroformed-nickel replicated grazing inci... more We present details of an MSFC development program of electroformed-nickel replicated grazing incidence optics for x-ray imaging. To date a wide variety of mirrors has been produced with diameters ranging from 2.5 cm, for small animal imaging, up to 112 meter, for x-ray astronomy. Around 100 intermediate size shells are currently aboard the HERO x-ray astronomy balloon payload awaiting launch in Fort Sumner, New mexico. Details of the program are presented together with developments currently underway to improve mirror-shell quality from the current approx. 15 arcsec resolution to below 10 arcsec for future x-ray astronomy missions.
Advancements in computer-controlled polishing, metrology, and replication have led to an x-ray mi... more Advancements in computer-controlled polishing, metrology, and replication have led to an x-ray mirror fabrication process that is capable of producing high-resolution Wolter microscopes. We present the fabrication and test of a nickel–cobalt replicated full-shell x-ray mirror that was electroformed from a finely figured and polished mandrel. This mandrel was designed for an 8-m source-to-detector-distance microscope, with 10× magnification, and was optimized to reduce shell distortions that occur within 20 mm of the shell ends. This, in combination with an improved replication tooling design and refined bath parameters informed by a detailed COMSOL Multiphysics® model, has led to reductions in replication errors in the mirrors. Mandrel surface fabrication was improved by implementing a computer-controlled polishing process that corrected the low-frequency mandrel figure error and achieved <2.0 nm RMS convergence error. X-ray tests performed on a pair of mirror shells replicated f...
We describe the fabrication and implementation of a high-resolution conical, grazing- incidence, ... more We describe the fabrication and implementation of a high-resolution conical, grazing- incidence, hard X-ray (20-70 keV) telescope. When flown aboard stratospheric balloons, these mirrors are used to image cosmic sources such as supernovae, neutron stars, and quasars. The fabrication process involves generating super-polished mandrels, mirror shell electroforming, and mirror testing. The cylindrical mandrels consist of two conical segments; each segment is approximately 305 mm long. These mandrels are first, precision ground to within approx. 1.0 micron straightness along each conical segment and then lapped and polished to less than 0.5 micron straightness. Each mandrel segment is the super-polished to an average surface roughness of approx. 3.25 angstrom rms. By mirror shell replication, this combination of good figure and low surface roughness has enabled us to achieve 15 arcsec, confirmed by X-ray measurements in the Marshall Space Flight Center 102 meter test facility. To image ...
Scheduled to launch in late 2021, the Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small E... more Scheduled to launch in late 2021, the Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small Explorer Mission in collaboration with the Italian Space Agency (ASI). The mission will open a new window of investigation – imaging Xray polarimetry. The observatory features 3 identical telescopes each consisting of a mirror module assembly with a polarization-sensitive imaging X-ray detector at the focus. A coilable boom, deployed on orbit, provides the necessary 4m focal length. The observatory utilizes a 3-axis-stabilized spacecraft which provides services such as power, attitude determination and control, commanding, and telemetry to the ground. During its 2-year baseline mission, IXPE will conduct precise polarimetry for samples of multiple categories of X-ray sources, with follow-on observations of selected targets.
The future X-ray observatory missions, such as International X-ray Observatory, require grazing i... more The future X-ray observatory missions, such as International X-ray Observatory, require grazing incidence replicated optics of extremely large collecting area (3 m2) in combination with angular resolution of less than 5 arcsec half-power diameter. The resolution of a mirror shell depends ultimately on the quality of the cylindrical mandrels from which they are being replicated. Mid-spatial-frequency axial figure error is a dominant contributor in the error budget of the mandrel. This paper presents our efforts to develop a deterministic cylindrical polishing process in order to keep the mid-spatial-frequency axial figure errors to a minimum. Simulation studies have been performed to optimize the operational parameters as well as the polishing lap configuration. Furthermore, depending upon the surface error profile, a model for localized polishing based on dwell time approach is developed. Using the inputs from the mathematical model, a mandrel, having conical approximated Wolter-1 g...
This slide presentation reviews the developments at Marshall Space Flight Center in fabricating E... more This slide presentation reviews the developments at Marshall Space Flight Center in fabricating Electroformed Nickel X-ray Optical devices. Missions that are using the mandrels created using the described process are reviewed, and improvements in the process of creating better quality mandrels are also reviewed. One of the processes, Electrochemically-Enhanced Mechanical Polishing (EEMP), is described. The Alignment and mounting system for full-shell replicated X-Ray Optics is shown, and the selective deposition process is also shown.
The Constellation-X mission, planned for launch in 2013, will feature an array of hard-x-ray tele... more The Constellation-X mission, planned for launch in 2013, will feature an array of hard-x-ray telescopes (HXT) with a total collecting area of greater than 1500 cm at 40 keV. Two technologies are currently being investigated for the optics of these telescopes including ...
ABSTRACT The Constellation-X (Con-X) mission planned for launch in 2015, will feature an array of... more ABSTRACT The Constellation-X (Con-X) mission planned for launch in 2015, will feature an array of Hard X-ray telescopes (HXT) with a total collecting area greater than 1500 cm2 at 40 keV. Two technologies are being investigated for the optics of these telescopes, including multilayer coated Electroformed-Nickel-Replicated (ENR) shells. The attraction of the ENR process is that the resulting full-shell optics are inherently stable and offer the prospect of better angular resolution which results in lower background and higher instrument sensitivity. We are building a prototype HXT mirror module using an ENR process to fabricate the individual shells. This prototype consists of 5 shells with diameters ranging from 150 mm to 280 mm with a length of 426 mm. The innermost of these will be coated with iridium, while the remainder will be coated with graded d-spaced W/Si multilayers. Parts I and II of this work were presented at the SPIE meetings in 2003 and 2004. This paper presents a progress update and focuses on accomplishments during this past year. In particular, we will present results from full illumination X-ray tests of multilayer coated shells, taken at the MPE-Panter X-ray facility.
We present details of an MSFC development program of electroformed-nickel replicated grazing inci... more We present details of an MSFC development program of electroformed-nickel replicated grazing incidence optics for x-ray imaging. To date a wide variety of mirrors has been produced with diameters ranging from 2.5 cm, for small animal imaging, up to 112 meter, for x-ray astronomy. Around 100 intermediate size shells are currently aboard the HERO x-ray astronomy balloon payload awaiting launch in Fort Sumner, New mexico. Details of the program are presented together with developments currently underway to improve mirror-shell quality from the current approx. 15 arcsec resolution to below 10 arcsec for future x-ray astronomy missions.
Advancements in computer-controlled polishing, metrology, and replication have led to an x-ray mi... more Advancements in computer-controlled polishing, metrology, and replication have led to an x-ray mirror fabrication process that is capable of producing high-resolution Wolter microscopes. We present the fabrication and test of a nickel–cobalt replicated full-shell x-ray mirror that was electroformed from a finely figured and polished mandrel. This mandrel was designed for an 8-m source-to-detector-distance microscope, with 10× magnification, and was optimized to reduce shell distortions that occur within 20 mm of the shell ends. This, in combination with an improved replication tooling design and refined bath parameters informed by a detailed COMSOL Multiphysics® model, has led to reductions in replication errors in the mirrors. Mandrel surface fabrication was improved by implementing a computer-controlled polishing process that corrected the low-frequency mandrel figure error and achieved <2.0 nm RMS convergence error. X-ray tests performed on a pair of mirror shells replicated f...
We describe the fabrication and implementation of a high-resolution conical, grazing- incidence, ... more We describe the fabrication and implementation of a high-resolution conical, grazing- incidence, hard X-ray (20-70 keV) telescope. When flown aboard stratospheric balloons, these mirrors are used to image cosmic sources such as supernovae, neutron stars, and quasars. The fabrication process involves generating super-polished mandrels, mirror shell electroforming, and mirror testing. The cylindrical mandrels consist of two conical segments; each segment is approximately 305 mm long. These mandrels are first, precision ground to within approx. 1.0 micron straightness along each conical segment and then lapped and polished to less than 0.5 micron straightness. Each mandrel segment is the super-polished to an average surface roughness of approx. 3.25 angstrom rms. By mirror shell replication, this combination of good figure and low surface roughness has enabled us to achieve 15 arcsec, confirmed by X-ray measurements in the Marshall Space Flight Center 102 meter test facility. To image ...
Scheduled to launch in late 2021, the Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small E... more Scheduled to launch in late 2021, the Imaging X-ray Polarimetry Explorer (IXPE) is a NASA Small Explorer Mission in collaboration with the Italian Space Agency (ASI). The mission will open a new window of investigation – imaging Xray polarimetry. The observatory features 3 identical telescopes each consisting of a mirror module assembly with a polarization-sensitive imaging X-ray detector at the focus. A coilable boom, deployed on orbit, provides the necessary 4m focal length. The observatory utilizes a 3-axis-stabilized spacecraft which provides services such as power, attitude determination and control, commanding, and telemetry to the ground. During its 2-year baseline mission, IXPE will conduct precise polarimetry for samples of multiple categories of X-ray sources, with follow-on observations of selected targets.
The future X-ray observatory missions, such as International X-ray Observatory, require grazing i... more The future X-ray observatory missions, such as International X-ray Observatory, require grazing incidence replicated optics of extremely large collecting area (3 m2) in combination with angular resolution of less than 5 arcsec half-power diameter. The resolution of a mirror shell depends ultimately on the quality of the cylindrical mandrels from which they are being replicated. Mid-spatial-frequency axial figure error is a dominant contributor in the error budget of the mandrel. This paper presents our efforts to develop a deterministic cylindrical polishing process in order to keep the mid-spatial-frequency axial figure errors to a minimum. Simulation studies have been performed to optimize the operational parameters as well as the polishing lap configuration. Furthermore, depending upon the surface error profile, a model for localized polishing based on dwell time approach is developed. Using the inputs from the mathematical model, a mandrel, having conical approximated Wolter-1 g...
This slide presentation reviews the developments at Marshall Space Flight Center in fabricating E... more This slide presentation reviews the developments at Marshall Space Flight Center in fabricating Electroformed Nickel X-ray Optical devices. Missions that are using the mandrels created using the described process are reviewed, and improvements in the process of creating better quality mandrels are also reviewed. One of the processes, Electrochemically-Enhanced Mechanical Polishing (EEMP), is described. The Alignment and mounting system for full-shell replicated X-Ray Optics is shown, and the selective deposition process is also shown.
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Papers by Chet Speegle